This invention generally relates to assemblies for delivering devices to a situs in a body passageway and in particular, to assemblies comprising an outer sheath containing an elongated catheter therein for delivering the distal portion of the catheter to a situs in a body passageway such as a blood vessel or bile duct. The assembly is adapted to be percutaneously inserted into a body passageway, sometimes by means of a guide catheter. For example, the assembly is introduced percutaneously into the femoral artery and then advanced, distally, through the arterial system to a desired situs, e.g. at the situs of an atherosclerotic lesion. Once located, the proximal end of the sheath may be manipulated so as to expose the distal portion of the catheter to the situs, whereafter the intended medical procedure may progress. For example, the so- located distal end of the catheter may include an inflatable balloon for carrying out a percutaneous translumenal coronary angioplasty procedure. Alternatively, a prosthesis such as a stent, graft, or stent/graft combination may be delivered, by the catheter to such situs. The situs need not be in a blood vessel but instead may be some other body passageway such as the urethra or a bile duct. Currently, procedures are performed for stenting such body passageways.
Descriptions of such procedures and the devices and apparatus associated therewith are exemplified by reference to the following U.S. Patents: U.S. Pat. No. 4,299,226 issued Nov. 10, 1981 to Banka; U.S. Pat. No. 4,323,071 issued Apr. 6, 1982 to Simpson, et al.; U.S. Pat. No. 4,581,017 issued Apr. 8, 1986 to Sahota; U.S. Pat. No. 4,748,982 issued Jan. 7, 1988 to Horzewski, et al.; U.S. Pat. No. 4,773,899 issued Sep. 27, 1988 to Spears; U.S. Pat. No. 4,848,344 issued Jul. 18, 1989 to Sos, et al.; U.S. Pat. No. 4,885,003 issued Dec. 5, 1989 to Hillstead; U.S. Pat. No. 4,932,959 issued Jun. 12, 1990 to Horzewski, et al.; U.S. Pat. No. 4,998,917 issued Mar. 12, 1991 to Gaiser, et al.; U.S. Pat. No. 4,998,923 issued Mar. 12, 1991 to Samson, et al.; U.S. Pat. No. 5,007,898 issued Apr. 16, 1991 to Rosenbluth, et al.; U.S. Pat. No. 5,034,001 issued Jul. 23, 1991 to Garrison, et al.; and U.S. Pat. No. 5,116,309 issued May 26, 1992 to Coll.
In carrying out the procedures described and exemplified above using heretofore available apparatus, several difficulties have been encountered and, while in some instances, the art has attempted to cure these difficulties, the state of the art is such that improvement is highly desired.
Specifically, one difficulty heretofore encountered is the problem of threading the elongated catheter through a tortuous passageway system. In doing so, one is faced with the requirement that the assembly have the requisite stiffness (often termed "pushability" in the art) to transmit the pushing forces exerted on the proximal end of the assembly and move the assembly in a distal direction through the passageway without the assembly bending, kinking, crimping or collapsing. At the same time, the assembly must be led through the tortuous passageway, conforming to all the bends and turns that are therein encountered. This need for both stiffness and conformability is in conflict and such conflict heretofore is manifested in disappointing and unsatisfactory performance of prior art devices.
Still another difficulty has been encountered in the employment of the subject devices. In pushing the assemblies through the body passageways, there is the great danger of abrading or otherwise traumatically affecting the inner walls of these passageways. The vascular system is particularly vulnerable to such undesirable abrasion. Still further, generally in connection with an emplaced sheath/contained catheter assembly, there is always the danger that the sheath will move relative to the catheter in an undesired direction, such undesired direction being generally the distal direction. Such movement, for example, during a procedure would obviously be disruptive. Accordingly, there is a need to obviate such undesired movement.